Cerebral hemodynamic responses induced by needling trigger points : a near infrared spectroscopic study

Abstract

Trigger points (TPs) are specific areas in the muscle, where characteristic symptoms such as referred pain are induced by pressing on those areas, and have been used to diagnose chronic pain syndrome such as myofascial pain syndrome and fibromyalgia. Acupuncture has been applied to TPs for treatment of chronic pain syndrome to induce specific sensation (de-qui: soreness, numbness, heaviness, and fullness), which has been used to assess effectiveness and adequacy of acupuncture stimulation. In the present study, we investigated relationships between de-qui sensation and cerebral hemodynamic responses using near infrared spectroscopy (NIRS). Acupuncture needle was inserted into the TPs of the right extensor muscle, and acupuncture manipulation (back-and-forth vertical movement) was applied for 8 trials of each 15 sec. The subjects were required to press a button when they felt de-qui sensation. The results indicated that Oxy Hb concentration was significantly decreased in the bilateral supplementary motor areas, compared with needling without any specific sensation. Previous studies reported that excessive motor outputs are one of causes of various chronic pain syndromes. The results suggest that acupuncture might ameliorate chronic pain by decreasing motor outputs. [J Physiol Sci. 2007;57 Suppl:S111]